One of the primary requirements of today's farmers on straw and chaff spreading systems are that they evenly distribute residue over a combine's entire cutting width. Often a straw chopper or spreading mechanism will be able to cover the cutting width of the combine, however equally important is the consistency of the spread.
Variables such as field's terrain, cutting height and wind direction alter the final placement of the residue. The cutting width of the machine may change regularly due to different headers that are quickly attached to the combine for different crops or conditions. The combine's headers can vary from a pick-up header, gathering in a swath that is cut from a pass as wide as 60 feet or as narrow as 18 feet, to an offset mounted 36 foot wide straight cut header. Many farmers want the spread width to be quickly and independently adjustable left to right while maintaining and even distribution of straw across the field. Many farmers would like to do this on the go from the seat of their cab.
Current methods to adjust the spread width involve adjustment of individual fins and/or changing the angle of the tailboard. The tailboard is easily adjusted on most systems however often the fins also need to be adjusted to eliminate the concentration of residue (rowing) in the field. Fin adjustment is very time consuming and is often not well understood by the operator. Typically an operator will adjust the fins once, most times guessing at a position and then living with the results.
Other systems allow similar adjustment of the tailboard and a single adjustment of all fins with a central lever or an electric actuator. These systems are quick and get the operator relatively close however often fine-tuning is never completed because of the complexity of the system and difficult methods to accommodate left to right differentiation.
Problems exist with existing technology. Current methods to manually change the spread width are time consuming and not well understood by the operator. High level of complexity to change spread distribution are problematic including linkages moving fins with individual adjustment.
U.S. Pat. No. 2,708,582—Adams—1955—Details an angular adjustable tailboard with adjustable fins mounted to the tailboard to vary spread width.
U.S. Pat. No. 4,921,469—Scharf—1990—Details a tailboard with a motorized fin control system. The system is designed with a single electric actuator and a linkage to vary the fin position. The linkage is designed to allow one side of the tailboard to position the fins generally straight while the other side is positioned outwards. The mechanism rotates the outer fins more than the inner to provide an even distribution as the spread width changes. An alternate embodiment details each fin set with a separate fully independent control. This is much more complex than the arrangement disclosed herein.
U.S. Pat. No. 5,569,081—Baumgarten—1996—A tailboard with motorized fin controls includes a wind sensor for detecting the speed and direction. In order to compensate for the wind the fins are automatically adjusted for optimum spread. The left and right fin sets are independently controlled.
U.S. Pat. No. 6,082,647—Claes—2000—A split chopper is disclosed with two complete choppers mounted at obtuse angles to each other.
U.S. Pat. No. 6,602,131—Wolters—2003—A flow guide with a horizontal axis is adjustable to vary the spread width
U.S. application Ser. No. 2002/0072400—Foth—2002— A tailboard with a motorized fin control where the fins continually move back and forth to eliminate rowing or more evenly distribute the residue.
U.S. application Ser. No. 2003/0162576—Buermann—2003—Fin Control Box/Monitor that is mounted in the cab to control the fin positions—the buttons on the monitor have a first control and a second selective operation.